Chemistry and Technology of Fuels and Oils, Vol.51, No.1, 79-86, 2015
Application of Laser Videographic Cryoscopic Micro Osmometry in Measurements of Temperature Depression in Petroleum Products
This paper describes using the familiar MT-2 platform to build an instrument capable of supporting dynamic observations and recording of the kinetics of physicochemical processes during cryoscopic osmometry of crude oil media and refined petroleum products in automatic mode. Modifications of the MT-2 design generally include introduction of a laser source, a videographic speckle recording system, a digitizing board for the speckle recording signal, a stepper motor control module and redesigned micromechanics controllable by it, which via signals supplied by the computer (the nature of which is controlled by specially written software) alters the movement of the analytical head. As a result of the modification, the MT-2 with digital speckle recording, laser module, and microcamera allows us: to determine the transition to irreversible aggregation of the asphaltenes, characterized by their deposition on the walls of the measuring bath (after desorption of the resins); to do realtime classification of crude oil by speckle morphometry methods; to observe and identify the emulsion properties of the crude oil, including formation of "carpenter's level" bubble inclusions and coacervate droplets; to carry out a rheological falling-drop experiment with thermographic monitoring; to make rheogoniometric observations while rotating the measuring instrument or thin cuvet; to observe wavy perturbations on the surface of the medium while the drop is falling, with delayed relaxation (dissipation) due to viscoelastic properties.
Keywords:cryoscopic osmometry;videographic micro osmometry;rheology;morphometry;speckle textures;topology